Knife



No Model.) J. JOHNSTON.

KNIFE.

NO. 433,793. Patented Aug. 5, 1890.

.- UNIT D STATES PATENT OFFICE.

ing had to the accompanying drawings,which ;1 provided with an extension on its inner end JAMES JOHNSTON, OF BRADFORD, PENNSYLVANIA.

KNIFE.

SPECIFICATION forming part of Letters Patent No. 433,793,dated August 5, 1890.

Application filedMay 29, 1890- Serial No. 353,650. (No model.)

To all whom it may concern.-

I Be it known that LJAMEs JOHNSTON, of

Bradford, in the county of McKean and State of Pennsylvania, have invented certain new and useful Improvements in Knives and Detachable Handles Therefor; and I do hereby V declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use it, reierence beform part of this specification.

My invention relates to an improvement in knives and detachable handles therefor; and

it consists in the combination of a handle and a bead or flange which extends across the end of this extension and having a flange in order to prevent the blade from having any lateral play, with the blade having a transverse groove to receive the flange or bead at some distance from its end, and a groove in 'i its end to receive the flange, which prevents lateral play, as will be more fully described hereinafter.

The object of my inventionis to especially I provide surgical knives with detachable han- 'dles and which handles are adapted to be applied to a number of different blades, and i ,blades, allow every portion of the blade to be which handles, when detached from the thoroughly dried and cleaned after having been boiled, and thus preventing any part 5 f from being exposed to rust. p

Figure 1 is a side elevation of a handle, to

which a blade is applied. Fig. 2 is a perspective of the handle alone.

spective of the blade alone.

A represents the handle, which is made of metal, and which is provided with the exten- Fig. 3 is a perside of its outer end. This extensionIis quite thin, but is as wide as the handle, and its flat 1nner face forms a surface, against which a caved or rounded out next to the extension, and at the center of this shoulder is formed the flange G, which serves to prevent the bladefrom having any lateral play.

The blade H is provided with a thickened -end I, and extending across near the inner end of this thickened portion I is the transverse groove J, in which the bead or flange 0 upon the handle catches for the purpose of holding the two parts in contact with each other. This bead or flange should first be inserted in the transverse groove while the two parts are held at a slight angle to each other, and then the two parts are straightened in a line with each other. The flat inner surface of this thickened portion I forms a bearing against which the extension B rests, and in the extreme outer end of the thickened part I is formed the groove 0, which receives the flange G for the purpose of locking the two parts in a line with each other. In order to separate the two parts, it is only necessary to hold the blade in one hand while an outward pressure is applied to the handle, and this pressure first forces the flange G out of the groove 0 and then the transverse flange or bead readily separates from the groove in which it fits.

By means of my invention an improved means of detachably fitting to a handle different blades or similar instruments is provided, and whereby one handle may answer for a number of different instruments. The handle and blade can be quickly secured .together and readily detached and either or both parts be boiled and thoroughly cleaned without any partbeing inaccessible, andthus exposed to rust. All pins, screws, ratchetwheels, catches, and springs of any description are done away with as being too troublesome and inaccessible, and hence are exposed to rustafter having been exposed to moisture.

Having thus described my invention, I claim- 1. The combination, with the handle having 011 its inner end an extension which has a curved shoulder at each of its ends, of a blade having an enlarged inner end which fits between and is engaged by the said shoulwhich prevents lateral movement, substa n- Io ders on the handle, substantially as shown. tially as shown.

2. The combination of the handle provided In testimony whereof Iaffix my signatnrein with an extension upon its end, a transverse presence of two witnesses.

5 bead or flange at the end of the extension, 4 7 T r and a second flange for preventing lateral JAMEb JOHLSION' movement, with the blade having a trans- Witnesses:

Verse groove to receive the bead or flange E. 0. NORTH, and a groove in its end to receive the flange H. H. NORTH. 

